ARP WATCH

Corporate policies prohibit the unauthorized connection of hardware to the company network, threatening dire consequences in the case of non-compliance. Fair enough, but how do you actually go about catching somebody trying to plug an illegal laptop into your Ethernet?

My choice for a faithful watchdog is Arpalert [1]. Arpalert creator Thierry Fournier recommends the following incantation to send the beast off into the wild: ./configure --prefix=/usr/local make make install This series of commands puts the C program in /usr/local/sbin and the arpalert.conf configuration file in /usr/local/etc/arpalert. No Place Like Home For my initial experiments, I decided to use a network that gives me excellent visibility, such as the network in my home office. It’s the weekend, and my wife has gone down to the local library, so I shouldn’t have more than four of five computers on the network. I did the following to launch Arpalert: /usr/local/sbin/arpalert

If protocols were human beings, NNTP would be a kind and slightly confused person that always believes the best of other people – even if they drop trash in the mailbox. Postfilter gives NNTP a watchdog.

Leafnode is a Usenet server for small sites where just a few users need access to a large number of groups. The Leafnode server is designed to recover from errors autonomously and needs very little attention.

On vacation we may be happy just to check the position of the sun,but computers need a more accurate measure of time. Luckily, there are atomic clocks that can receive time signals by radio and off the Internet.